Bloopers & Behind The Scenes on Instagram: "Frank Costanza, portrayed by Jerry Stiller, is one of the most explosive and memorable characters in Seinfeld. As George Costanza’s hot-headed, brutally honest father, Frank is known for his constant yelling, unpredictable mood swings, and complete lack of social filter. His larger-than-life moments—like inventing Festivus, shouting “Serenity now!”, and launching into angry monologues over the smallest inconveniences—turned him into a fan favorite. Fra